"Other real-time editors like Google Docs work by broadcasting an updated copy of the document to everyone every 15 seconds. This creates a noticeable lag that gets in the way of collaboration. You start editing something, only to find 10 seconds later that someone else deleted it. Etherpad updates every copy of the document every half second. This 30x increase in speed changes the experience completely. Your edits hardly ever clash with other users'. So you work confidently instead of tentatively." (from EtherPad's site)